T400 help please
 

I have a 383 with a T400 transmission and BTE 310800 11” converter Stall Speed 2600-2800 rpm.
On my last drive the trans would not shift until it reached 4000rpm.
What could be going wrong?
What should I look for?

Thank You

Re: T400 help please
 

Check the vacuum line for full vacuum.

Re: T400 help please
 

Vacuum line most likely---OR the governor (under the 4 bolts on the side) has stripped a gear from the bushing walking in the case

Re: T400 help please
 

Thanks guys, I know the vacuum line is hooked up but, what's the best way to test it?

Re: T400 help please
 

Hook a vacuum gauge to the line at the trans

Re: T400 help please
 

I had same issue bit I had my vacuum advance cannister off the HEI T-d into it. The diaphragm in the cannister went bad and raised my shift points like you.

Re: T400 help please
 

i have my vacuum line straight to the intake on a Edelbrock pro flow 4. I made sure and use hard line for most of the route with rubber fittings on the ends.
I'll get a chance to look at it this weekend. Hopefully its just a line that came unattached.

Re: T400 help please
 

Well, I tested vacuum at the transmission it was 20-22 at 3000rpm. Does that sound about right?
Then I checked the kick down switch and it was stuck on. I took the Lokar switch apart and sprayed it with silicone lube. That seems to have done the trick. All is well now, thanks for the help.